need 'this' to access data member

[Derek Parnell]

On Tue, 26 Sep 2006 22:22:05 -0500, clayasaurus wrote:

> Hi, I have the following code attached, and I do not understand why I 
> can not access this data member. Help is very much appreciated, thanks.

As explained already, a named union/struct must also have a data
declaration before you can refer to its members. However, have you
considered anonymous union/struct ? When you use these, you can refer to
the members without having to qualify their names.

import std.stdio;
// datafield hacks
alias int FILE;
alias int Uint8;

// structure
struct SDL_RWops
{

    int (*seek)(SDL_RWops *context, int offset, int whence);
    int (*read)(SDL_RWops *context, void *ptr, int size, int maxnum);
    int (*write)(SDL_RWops *context, void *ptr, int size, int num);
    int (*close)(SDL_RWops *context);
    uint type;

    union
    {
        version(Windows)
        {
            struct
            {
                int append;
                void *h;
            }
        }
        struct
        {
            int autoclose;
            FILE *fp;
        }
        struct
        {
            Uint8 *base;
            Uint8 *here;
            Uint8 *stop;
        }
        struct
        {
            void *data1;
        }
    }
}


int main()
{
    SDL_RWops w;

    // need 'this' to access data member data1??
    std.stdio.writefln("autoclose A:" , w.autoclose);

    w.data1 = &w; // sample data
    std.stdio.writefln("autoclose B:" , w.autoclose);

    version(Windows)
    {
     w.append = 42; // sample data
     std.stdio.writefln("autoclose B:" , w.autoclose);
    }
    return 0;
}



-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
"Down with mediocrity!"
27/09/2006 3:22:49 PM